25 research outputs found

    FTIR-ATR spectroscopy applied to quality control of grape-derived spirits

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    The Fourier transform infrared (FTIR) spectroscopic method with attenuated total reflectance (ATR) was used for predicting the alcoholic strength, the methanol, acetaldehyde and fusel alcohols content of grape-derived spirits. FTIR-ATR spectrum in the mid-IR region (4000-400 cm -1 ) was used for the quantitative estimation by applying partial least square (PLS) regression models and the results were correlated with those obtained from reference methods. In the developed method, a cross-validation with 50% of the samples was used for PLS analysis along with a validation test set with 50% of the remaining samples. Good correlation models with a great accuracy were obtained for methanol (r 2 = 99.4; RPD = 12.8), alcoholic strength (r 2 = 97.2; RPD = 6.0), acetaldehyde (r 2 = 98.2; RPD = 7.5) and fusel alcohols (r 2 from 97.4 to 94.1; RPD from 6.2 to 4.1). These results corroborate the hypothesis that FTIR-ATR is a useful technique for the quality control of grape-derived spirits, whose practical application may improve the efficiency and quickness of the current laboratory analysis.The authors thank the technical support of Amélia Soares, Deolinda Mota and Otília Cerveira and the support of Centro de Estudos Florestais, a research unit funded by FCT (PEst-OE/AGR/ UI0239-2014) and Instituto de Ciências Agrárias e Ambientais Mediterrânicas, a research unit funded by FCT (PEst-OE/AGR/ UI0115/2014). The authors also thank to Centro de Biotecnologia de Plantas da Beira Interior for the FTIR-ATR equipment and software OPUS availability.info:eu-repo/semantics/publishedVersio

    Physicochemical characterization of Lavandula spp. honey with FT-Raman spectroscopy

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    This study aimed to evaluate the potential of FT-Raman spectroscopy in the prediction of the chemical composition of Lavandula spp. monofloral honey. Partial Least Squares (PLS) regression models were performed for the quantitative estimation and the results were correlated with those obtained using reference methods. Good calibration models were obtained for electrical conductivity, ash, total acidity, pH, reducing sugars, hydroxymethylfurfural (HMF), proline, diastase index, apparent sucrose, total flavonoids content and total phenol content. On the other hand, the model was less accurate for pH determination. The calibration models had high r 2 (ranging between 92.8% and 99.9%), high residual prediction deviation - RPD (ranging between 4.2 and 26.8) and low root mean square errors. These results confirm the hypothesis that FT-Raman is a useful technique for the quality control and chemical properties’ evaluation of Lavandula spp honey. Its application may allow improving the efficiency, speed and cost of the current laboratory analysis.Acknowledgements: CEF is a research unit funded by Fundação para a Ciência e a Tecnologia I.P. (FCT), Portugal (UID/AGR/00239/2013). Centre of Molecular and Environmental Biology is a research unit funded by FCT, UID/BIA/04050/2013 (POCI-01–0145-FEDER-007569) and by the ERDF through the COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI).info:eu-repo/semantics/publishedVersio

    Application of FTIR-ATR spectroscopy on the bee pollen characterization

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    Bee pollen contains almost all nutrients required by the human organism as well as diverse health-promoting substances. However, its composition and nutritional value greatly depend on the botanical origin. As such, it is important to develop a rapid and non-expensive methodology that allows studying its characteristics, making labelling more objective and easier. The FTIR-ATR technique was used to predict some nutritional parameters in 126 bee pollen samples. FTIR-ATR spectrum obtained in the region between 4000 and 400 cm -1 with PLS Regression models were used to correlate spectral information with the data obtained using reference methods. In this first approach with pollen samples, good correlation models with appropriate accuracy were obtained for the evaluated parameters with r 2 varying from 74.8 to 97% and residual prediction deviation between 2.0 and 5.8. These results suggest that FTIR-ATR may be a useful technique for assessing bee pollen’s composition.Centro de Estudos Florestais is a research unit funded by FCT (PEst-OE/AGR/UI0239-2014). Centre of Molecular and Environmental Biology is a research unit funded by FCT, UID/ BIA/04050/2013 (POCI-01-0145-FEDER-007569) and by the ERDF through the COMPETE2020 – Programa Operacional Competitividade e Internacionalizac¸a˜o (POCI).info:eu-repo/semantics/publishedVersio

    Wild flower resources and insect honeydew are potential food items for Elasmus flabellatus

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    Adult parasitoids need non-host food such as nectar or honeydew for survival and reproduction. In a conservation biological control strategy, the knowledge about non-host feeding of parasitoid species is a key factor to successfully increase their action. The nutritional behavior of Elasmus flabellatus (Fonscolombe) (Hymenoptera: Eulophidae), a major parasitoid of the olive moth, Prays oleae (Bernard) (Lepidoptera: Praydidae), is completely unknown. Survival experiments were performed on two secondary olive pest honeydews and eight common flowering plant species in order to analyze their suitability as potential food sources for E. flabellatus females. Abdomen and gut dissections were carried out to verify the pollen consumption and the egg production. Floral architecture and insect morphology were described. Cox’s proportional hazard regression models were used to analyze the differences between parasitoid survivals. Honeydews secreted by Saissetia oleae (Olivier) (Hemiptera: Coccidae) and Euphyllura olivina (Costa) (Hemiptera: Psyllidae) resulted in the best performance followed by the flowers of Malva sylvestris L. (Malvaceae), Daucus carota L. (Apiaceae), and the Cichorioideae Tolpis barbata (L.) and Andryala integrifolia L. Theoretical flower resources accessibility were assessed and related with the survival results. E. flabellatus females did not consume pollen and did not produce eggs, suggesting that the species is synovigenic and requires additional foods for egg production. In sustainable pest control programs, this novel knowledge is a prom ising opportunity for improving suitable food resources of E. flabellatus in the field.The authors are grateful to the Portuguese Foundation of Science and Technology for financial support through the project EXCL/AGR-PRO/0591/2012 “Olive crop protection in sustainable production under global climatic changes: linking ecological infrastructures to ecosystem functions.” M.V. thanks FCT, POPHQREN, and FSE for the PhD grant (SFRH/BD/70693/2010). This manuscript is part of M.V.’s PhD thesis.info:eu-repo/semantics/publishedVersio

    Pollen feeding habits of Chrysoperla carnea s.l. adults in the olive grove agroecosystem

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    Chrysoperla carnea s.l. (Stephens) larvae are important natural enemies in agroecosystems. However, adults feed on honeydew excreted by hemipterans, and pollen and nectar from flowering plants. Pollen is essential for egg production, but to our knowledge, the pollen diet of C. carnea in perennial crops has never been addressed. In this work, the objective was to study the diversity and potential selection of pollen types consumed by C. carnea in the olive grove agroecosystem. For this study, C. carnea adults were captured from April to December of 2012 and 2013, and simultaneously, inventories of the plant diversity were obtained in olive orchards and adjacent scrubland and herbaceous patches. The pollen types contained in C. carnea guts were identified by microscopy and compared with the pollen types in the environment using Jacobs`s second selection index. The results indicated that (i) C. carnea females and males captured in the olive tree canopy visited scrub and herbaceous vegetation patches; (ii) they fed on different anemophilous and entomophilous pollen types from tree and scrub (Olea europaea, Fabaceae, Pinaceae, Cistaceae or Ericaceae) and herbaceous (Asteraceae, Apicaceae, Brassicaceae, Poaceae, Rumex type or Plantago type) strata; and (iii) adults fed not only on flowers but also on pollen settled on vegetation surfaces. Here, we demonstrated that C. carnea could benefit not only from the diversity of entomophilous pollen during the plant flowering periods but also from other pollens that could remain in the environment in different periods. This has important implications for the management of the floral diversity adjacent to the crop.The authors are grateful to the Portuguese Foundation of Science and Technology for financial support through the project EXCL/AGRPRO/ 0591/2012 “Olive crop protection in sustainable production under global climatic changes: linking ecological infrastructures to ecosystem functions.” M.V. thanks FCT, PostDoc grant (SFRH/BPD/ 119487/2016).info:eu-repo/semantics/publishedVersio

    Syrphids feed on multiple patches in heterogeneous agricultural landscapes during the autumn season, a period of food scarcity

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    Many syrphid larvae are predators and have an important role as biological control agents of pests in agroecosystems. However, adults feed on non-prey resources such as pollen from flowers. Heterogeneous landscapes can provide syrphids with a great biodiversity of plants and ensure the existence of food resources. This is particularly important during periods of food scarcity, such as autumn, for syrphid species that spend those periods as adults. Nevertheless, the feeding habits of syrphid adults in resource-scarce agroecosystems are poorly known. In this study, the pollen consumption and preferences of Eupeodes corollae (Fabricius) and Episyrphus balteatus (De Geer) were analyzed in olive groves and surrounding herbaceous and woody patches in the autumns of 2012 and 2013 in northeastern Portugal. The guts were dissected, and the pollen types were identified and compared with the ground cover plants in the studied patches. Both species consumed and selected pollen types from herbaceous and woody vegetation that occurred in different patches, indicating that they flew between patches. These results highlight the importance of conserving heterogeneous agricultural landscapes to guarantee the existence of food resources for beneficial insects during periods of scarcity.The authors are grateful to the Foundation for Science and Technology (Portugal) and COMPETE/QREN/EU for financial support through the research project EXCL/AGR-PRO/0591/2012: Olive crop protection in sustainable production under global climatic changes: linking ecological infrastructures to ecosystem functions and for grant SFRH/BD/70693/2010 awarded to M. Villa. The authors are also grateful to Carlos Aguiar for help with the plant species identification.info:eu-repo/semantics/publishedVersio

    Evaluation of FT-Raman and FTIR-ATR spectroscopy for the quality evaluation of Lavandula spp. Honey

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    Monofloral Lavandula spp. honey is very appreciated by consumers due to its characteristic and pleasant aroma and flavor. Given the economic importance of this type of honey, it is important to develop a rapid and non-expensive methodology that allows certifying its quality. In this context, this study aimed to compare the applicability and accuracy of FTIR-ATR and FT-Raman techniques for the quality evaluation of Lavandula spp. honey. Calibration models, with PLS regression models, were obtained for both methodologies concerning the following parameters: total acidity, reducing sugars, hidroximetilfurfural (HMF), electrical conductivity, ash, proline content, diastase activity, apparent sucrose, total flavonoids, and total phenolic contents. The calibration models had high regression coefficients, r2 (FTIR-ATR: 0.965–0.996; FT-Raman: 0.983–0.999), high ratios of performance to deviation, RPD (FTIR-ATR: 5.4–15.7; FT-Raman: 7.6–53.7), and low root mean square errors (RMSEs; FTIR-ATR: 0.005–3.0; FT-Raman: 0.004–1.02). These results corroborate the potentiality of FTIR-ATR and FT-Raman for quality evaluation and evaluation of the chemical properties of Lavandula spp. honey even though FT-Raman technique provided more accurate models.Centro de Estudos Florestais is a research unit funded by FCT (UIDB/00239/2020). Financial support is acknowledged to CIMO Research Centre, a research unit funded by FCT (project Ref.a UIDB/00690/2020) and supported by Polytechnic Institute of Bragança. Financial support for publication is acknowledged to CERNAS Research Centre, a research unit funded by FCT (project Ref.a UIDB/00681/2020) and supported by Polytechnic Institute of Viseu. The Open Access Article Processing Charges was funded by CERNAS Project (project Ref.a UIDB/00681/2020). This research was funded by the Forest Research Centre, a research unit funded by Fundação para a Ciência e a Tecnologia I. P. (FCT), Portugal (UIDB/ 00239/2020), and CIMO Research Centre, a research unit funded by FCT (FCT), Portugal (UIDB/00690/2020) and supported by Polytechnic Institute of Bragança.info:eu-repo/semantics/publishedVersio

    Biodiversity and pollen feeding habits of syrphids in olive groves and surrounding landscape in Northeastern Portugal during spring

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    Many syrphid larvae are predators of aphids and early stages of moths and psyllids, being potential control agents of some olive pests. However, adults need pollen and nectar for energy and reproduction. An increase of plant resources biodiversity in heterogeneous landscape could benefit these natural enemies. Thus, our goal of was to study the syrphid biodiversity and their pollen sources in olive agroecosystems from the northeast of Portugal during spring, that coincides with the availability of pests. For that, syrphids were captured in three not-tilled olive groves and two surrounding field areas (an herbaceous vegetation patch and a scrubland) next to each olive grove. Simultaneously, flowering plant inventories were carried out. Syrphids and the pollen contained in the guts of the most abundant species were identified. Thereafter pollen in guts was compared with pollen in the environment to evaluate a potential pollen selection. The most abundant species were Sphaerophoria scripta and Melanostoma mellinum. During the spring syrphids did not consume all the occurring plant species but did not actively selected pollen types. Results indicated that Asteraceae, Plantaginaceae, Caryophyllaceae, Echium type, Rumex type and Jasione type are important food sources for M. mellinum and S. scripta. These results will allow managing ground cover vegetation more efficiently in order to conserve syrphids in the olive agroecosystem.M. Villa is grateful to the Foundation for Science and Technology (Portugal) for the postdoctoral grant SFRH/BPD/119487/2016info:eu-repo/semantics/publishedVersio

    MEtop - a generator for single top production via FCNC interactions

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    We present a generator for single top quark production via flavour-changing neutral currents. The MEtop event generator allows for Next-to-Leading-Order direct top production pptpp \to t and Leading-Order production of several other single top processes. A few packages with definite sets of dimension six operators are available. We discuss how to improve the bounds on the effective operators and how well new physics can be probed with each set of independent dimension six operators.Comment: 26 pages, 22 figure

    A História da Alimentação: balizas historiográficas

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    Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema
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